diff --git a/pywb/rewrite/html_rewriter.py b/pywb/rewrite/html_rewriter.py
index 9d1310b1..25f23d70 100644
--- a/pywb/rewrite/html_rewriter.py
+++ b/pywb/rewrite/html_rewriter.py
@@ -101,6 +101,7 @@ class HTMLRewriterMixin(object):
self.head_insert = head_insert
self.parse_comments = parse_comments
+ self.defmod = defmod
self.rewrite_tags = self._init_rewrite_tags(defmod)
# get opts from urlrewriter
@@ -391,7 +392,14 @@ class HTMLRewriter(HTMLRewriterMixin, HTMLParser):
def handle_comment(self, data):
self.out.write('